Is this normal?? They just installed Invidia TBE today and on my way home I notice that my boost is less than before. (Meaning 4th gear pull 1.4, after install 4th gear pull, 1.2) I know I need a boost controller but i was just wondering if this is normal. thanks...

 

No, it's not normal. The norm is for boost to RISE due to the lessened backpressure. In fact, it usually rises enough to cause fuel cut on untuned cars with no MBC.

 

so you think I might have a boost leak??

 

Boost leaks don't usually manifest themselves in terms of suddenly seeing 3psi less than normal unless it's a huge leak. If you had a huge leak, I think you'd hear it, but it's possible you have one. I don't know how it could happen after a TBE install, though.

 

what you mean by fuel cut? is it gonna run lean with an untuned tbe?

 

Fuel cut when it sees too much boost.

 

I experienced a mild boost gain once I installed Buschur's TBE. At most, maybe 1 psi.

Then again, we are a mile high...

 

Fuel cut has nothing to do with running lean and is not caused directly by boost levels, however it is related.

Fuel cut is when your stock ECU reads a certain amount of airflow across the MAF that is above the built-in threshold, so it cuts fuel to "protect" the engine. Generally, it happens when people raise boost above stock without a tune like a Dynoflash that removes fuel cut. Just adding a TBE usually causes a rise in boost of sometimes 2-3psi due to the lessened backpressure, which then causes fuel cut in higher gears at higher rpms.

 

You think I might need a Boost controller and hopes it will fix the problem??

 

Yeah, an MBC is $85 while the exhaust was $600? As long as you have a boost gauge already (sounds like you do), then you can add the MBC and regulate boost just fine. However, I'd do a pressure test while installing the MBC.

 

Thanks for your input guys. I really appreciate it.